OBJECTIVE To assess the effects of early recurrent otitis media on linguistic development in children. We especially wanted to determine the possible significant consequences of early recurrent otitis media at school age. METHODS We collected data retrospectively on recurrent otitis media episodes from the parents of 394 children in 18 school classes selected at random in a middle-sized city in Finland. Auditory comprehension was tested with a subtest of the Illinois Test of Psycholinguistic Ability, picture vocabulary with the Peabody Picture Vocabulary Test (revised test version), morphologic competence with a Finnish Morphological Test and reading comprehension with a test designed for this purpose. RESULTS Children with more than four otitis episodes before the age of 3 years performed less well in the reading comprehension test (P = 0.01 to 0.02) than children with fewer otitis media episodes. Multiple regression analysis adjusted for the confounding variables showed early otitis media to be associated with impaired reading comprehension test scores (regression coefficient -0.1245, 95% confidence interval -0.2245 to -0.0245, P = 0.01), which also correlated significantly with the teachers' evaluation of the student's reading comprehension (Spearman rank correlation r = 0.5, P < 0.01). Otitis episodes after the age of 3 years were not associated with abnormal test results. CONCLUSIONS Middle ear disease in infancy had a significant adverse effect on reading comprehension as late as 9 years of age, even among children whose acute episodes were effectively treated.